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This blog is predominately about camera trapping in California. We camera trap to save our souls and to teach primary school students about biology and conservation. We will also touch on other camera trapping news and musings, sets from afar, mediocre herpetology, sucky birding, and other natural history discussions.

Sunday, January 30, 2011

The other week I uploaded some videos to show my 6th graders the results of the camera that they set up. One video in particular that they enjoyed showed a bobcat rubbing its cheek on the camera itself.

Later, a question was raised by a fellow camera trap warrior - was this a bobcat? Could it actually be a domestic cat?I had just assumed that any feline-looking creature captured by our cameras would be a bobcat. The thought that a domestic cat would be wondering around wild West Marin never entered my mind.

I then began to ask the simple questions that lead to bobcat identification -- does it have black tufted ears, spotted coat, black barring on the legs, etc.

The video offers few answers, with its low quality and limited view of the animal.

You also see a somewhat bushy tail and a compact body -- allowing for the domestic cat thought to remain, but a final decision still inconclusive.

It is here where the still camera 25 feet down the trail becomes our ally.

6 minutes earlier (according to the timestamp) a bobcat comes up the trail towards the video cam.When reviewing previous data, however, a discrepancy between the internal clocks is observed of about 6 minutes, in favor of the video cam. This is determined by comparing shots that show the IR flash of each camera and a similar capture, whether it be with animal or a blank scene.

Still, the case is not solved. Perhaps these are two separate visits, with the bobcat close behind, tracking its cousin?

Luckily our cheek-rubber visited the video cam two other times. The still camera also made captures at similar times.

12.1

12.1

12.2

12.2

A close look at the 12.2 video offers up this washed out still:

black barring on hind leg?

This is all the evidence.

What say you?

Just another bobcat, or a bold and curious domestic cat off on adventure?

Thursday, January 27, 2011

The Franciscan Manzanita once thought extinct was saved when a lone plant was found on a median during Golden Gate Bridge construction. It is now being propagated through clones at Arboretums around the state including UCSC. Our friends at Audubon Canyon Ranch in Marin played an instrumental role in relocating the plant from the median a year ago yesterday. A year to the date later, young clones are hitting the soil in places around California.

Rescued from the verge of extinction, a single wild specimen of a rare California plant now has hundreds of progeny -- celebrated Wednesday in a festive planting ceremony at the UC Santa Cruz Arboretum.

A reversal of fate at a time of so many tough environmental challenges, the future of the Franciscan manzanita now seems secure.

On a sun-drenched afternoon, two of the precious seedlings were nestled into holes along an ocean-facing hillside, gently covered with soil, then ogled by admirers.

Tuesday, January 11, 2011

The set was up for a total of 15 days and bobcats showed up during the second week too.

In two weeks we had 12 visits with 13 bobcats total. One visit had two bobcats in the same visit. In the 12 visits there are at least two individuals, but likely three. I don't think there was any more than three bobcats captured at this set. The time between visits ranged from 1.5 hours to 100 hours with a mean species visit interval of 33 hours. I define a visit as >1 hour between images of the same species. Visits were split roughly evenly between day and IR images. This was a well lit set so IR correlated well with the sun being below the horizon. Below is a graph of the visits binned into hour intervals for bobcats and coyotes for this set, with yellow being daylight hours and gray being night hours. Clicking on the graph will enlarge it.

Some data of interest for this set is as follows:

Data of Interest

# of pics

68

# not "test" pic

52

# of ID species

9

# of CT days

15

# of visits

26

# of misfires

5

# of test shots

16

# of triggers

52

Pos triggers

47

Pos trig %

90.4

Neg Trig %

9.6

visits/CT day

1.73

trigger/CT day

3.5

Pos trigger/day

3.1

IR images

24

Color Images

28

# of indiv

36

# of birds

15

# of mammals

32

# or small mammals

0

# of med mammals

31

# of lrg mammals

1

The number of birds, small mammals etc are the number of images not visits. I still have to work out the complicated excel equation to get more precise visit data grouped by type of animal. Complicating the equation is if there is more than one animal in a visit, for example gangs of raccoons. In that case, I think the total would be more informative as four "individual raccoons" rather than one "raccoon visit," but hopefully I will have that worked out shortly.

I did not ID all birds in this set hence the number of ID species being lower than it could be. I will discuss the birds of this set once I finish IDing some of the Little Brown Birds. With almost 2 visits a day and a positive trigger percentage over 90% I was quite please with this set despite the very heavy rain that occurred throughout most of it. Bobcats were the most frequent visitors, followed by birds in general and then raccoons and coyotes.

The non-bird species list at this set was Bobcat, Coyote, Raccoon, BT deer and Striped Skunk.

The IR flash seems to be worse and blowout even more in wet conditions so this first photo is even worse than normal but shows two bobcats. The previous photo in the series had the bobcat at the top of the slope in a crouched laying down position while the second one was just coming into frame at the bottom of the slope as if waiting in ambush. I like to think it was the youngster getting ready to play attack mom. I am going to have to do like the Codger and try and dim my IR flash a bit. Maybe RandomTruth's upcoming post may have some more ideas on doing this.

Wednesday, January 5, 2011

The City of DeLand, Florida is having some issues with Black Vultures which reminded me of the story of the California Condors on the Big Sur Coast that were causing all kinds of problems, ripping the roof off of the house at Grimes Point, but I cannot find the citation for it at the moment.

Sunday, January 2, 2011

A couple of River otter sightings in Marin and Sonoma Counties this past week for your enjoyment ...

The first on my radar was a sighting by local photographer Donald Kinney. Donald usually does street photography and Marin County landscapes especially those involving water. So it was a real treat for him to see some of our local wildlife that he had never seen before and was not real familiar with.